535 research outputs found

    Isotope effects in switchable metal-hydride mirrors

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    Measurements of optical reflectance, transmittance, and electrical resistivity on the switchable mirror systems YHx and YDx show that the absorption of hydrogen induces the same variations as that of deuterium. In both cases there is a weak transparency window for the metallic dihydride (dideuteride) phase and a yellowish transparency in the insulating trihydride (trideuteride) phase. The slightly higher electrical resistivity of the deuterides is related to the lower energy of their optical phonons. The absence of significant isotope effects in the optical properties of YHx(YDx) is at variance with Peierls-like theoretical models. It is, however, compatible with strong electron correlation model

    The relations between work centrality, psychological contracts, and job attitudes: the influence of age

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    The current study sought to explain a largely overlooked theme in psychological contract literature, that is, how individual factors are related to formation of psychological contract. It investigated the relationship between people’s work centrality, psychological contracts, and job attitudes. It was expected that people with higher work centrality would be less likely to have a transactional contract and more likely to have a relational contract with the employer. Furthermore, it was expected that psychological contract (transactional and relational) would mediate the relations between work centrality and job attitudes. Finally, we expected age to moderate the relations between work centrality and the psychological contract. The study was conducted among 465 employees in a Dutch health care organization. Structural equation models supported the mediating effect of psychological contract types in the relations between work centrality and three job attitudes (work engagement, job satisfaction, and turnover intention). Moreover, it was found that the relations between work centrality and psychological contract were stronger for older workers than for younger workers

    Entrepreneurs’ age, institutions, and social value creation goals: a multi-country study

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    This study explores the relationship between an entrepreneur's age and his/her social value creation goals. Building on the lifespan developmental psychology literature and institutional theory, we hypothesize a U-shaped relationship between entrepreneurs’ age and their choice to create social value through their ventures, such that younger and older entrepreneurs create more social value with their businesses while middle age entrepreneurs are relatively more economically and less socially oriented with their ventures. We further hypothesize that the quality of a country’s formal institutions in terms of economic, social, and political freedom steepen the U-shaped relationship between entrepreneurs’ age and their choice to pursue social value creation as supportive institutional environments allow entrepreneurs to follow their age-based preferences. We confirm our predictions using multilevel mixed-effects linear regressions on a sample of over 15,000 entrepreneurs (aged between 18 and 64 years) in 45 countries from Global Entrepreneurship Monitor data. The findings are robust to several alternative specifications. Based on our findings, we discuss implications for theory and practice, and we propose future research directions

    Does methylphenidate improve inhibition and other cognitive abilities in adults with childhood-onset ADHD?

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    Contains fulltext : 48908.pdf (publisher's version ) (Closed access)We examined the effect of methylphenidate (Mph) on inhibition and several other cognitive abilities in 43 adults with Attention Deficit Hyperactivity Disorder (ADHD) by use of Conners' Continuous Performance Test (CPT) and the Change Task (ChT), an extension of the Stop Signal Test (SST). In a double blind, cross-over, placebo controlled study with Mph, tests were administered during the third week of individually titrated treatment with Mph (maximum dose 1 mg / kg / day) and during the third week of treatment with placebo. We established large medication effects for commission errors, standard error of mean reaction time, and attentiveness on the CPT, as well as moderate medication effects for mean reaction time on the CPT and response re-engagement speed on the ChT. For Stop Signal Reaction Time (SSRT) on the ChT, we also established large effects of Mph, but only in a group of participants who showed slow SSRTs on placebo. Mph indeed ameliorates inhibition, which is the core problem of ADHD, and certain other cognitive abilities in adults with ADHD

    Sex-Based Differences in Treatment with Immune Checkpoint Inhibition and Targeted Therapy for Advanced Melanoma:A Nationwide Cohort Study

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    SIMPLE SUMMARY: Melanoma is a malignant form of skin cancer. The overall survival of patients with advanced stages of disease were initially low. Fortunately, in recent years systemic treatment with immunotherapy has prolonged survival. We set out to answer the question whether men and women with advanced melanoma differ in prognostic factors, tumor-response to immunotherapy, and treatment-related adverse events. All patients in the Netherlands were registered between July 2013 and July 2018. We showed that although clinical and tumor characteristics differ, the safety profile of immunotherapy is comparable. Furthermore, overall, a 10% survival advantage for women was seen. Following immunotherapy there was no survival difference. ABSTRACT: Recent meta-analyses show conflicting data on sex-dependent benefit following systemic treatment for advanced melanoma patients. We examined the nationwide Dutch Melanoma Treatment Registry (July 2013–July 2018), assessing sex-dependent differences in advanced melanoma patients (stage IIIC/IV) with respect to clinical characteristics, mutational profiles, treatments initiated, grade 3–4 adverse events (AEs), treatment responses, and mortality. We included 3985 patients, 2363 men (59%) and showed that although men and women with advanced melanoma differ in clinical and tumor characteristics, the safety profile of immune checkpoint inhibition (ICI) is comparable. The data suggest a 10% survival advantage for women, mainly seen in patients ≥60 years of age and patients with BRAF V600 mutant melanoma. Following ICI there was no survival difference

    Checkpoint inhibitor induced hepatitis and the relation with liver metastasis and outcome in advanced melanoma patients

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    BACKGROUND: Checkpoint inhibitor-induced hepatitis is an immune-related adverse event of programmed cell death protein 1 (PD-1) inhibition, cytotoxic T-lymphocyte associated 4 (CTLA-4) inhibition or the combination of both. Aim of this study was to assess whether checkpoint inhibitor-induced hepatitis is related to liver metastasis and outcome in a real-world nationwide cohort. METHODS: Data from the prospective nationwide Dutch Melanoma Treatment Registry (DMTR) was used to analyze incidence, risk factors of checkpoint inhibitor-induced grade 3–4 hepatitis and outcome. RESULTS: 2561 advanced cutaneous melanoma patients received 3111 treatments with checkpoint inhibitors between May 2012 and January 2019. Severe hepatitis occurred in 30/1620 (1.8%) patients treated with PD-1 inhibitors, in 29/1105 (2.6%) patients treated with ipilimumab and in 80/386 (20.7%) patients treated with combination therapy. Patients with hepatitis had a similar prevalence of liver metastasis compared to patients without hepatitis (32% vs. 27%; p = 0.58 for PD-1 inhibitors; 42% vs. 29%; p = 0.16 for ipilimumab; 38% vs. 43%; p = 0.50 for combination therapy). There was no difference in median progression free and overall survival between patients with and without hepatitis (6.0 months vs. 5.4 months progression-free survival; p = 0.61; 17.0 vs. 16.2 months overall survival; p = 0.44). CONCLUSION: Incidence of hepatitis in a real-world cohort is 1.8% for PD-1 inhibitor, 2.6% for ipilimumab and 20.7% for combination therapy. Checkpoint inhibitor-induced hepatitis had no relation with liver metastasis and had no negative effect on the outcome. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12072-021-10151-4

    Preclinical characterization and target validation of the antimalarial pantothenamide MMV693183

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    Drug resistance and a dire lack of transmission-blocking antimalarials hamper malaria elimination. Here, we present the pantothenamide MMV693183 as a first-in-class acetyl-CoA synthetase (AcAS) inhibitor to enter preclinical development. Our studies demonstrate attractive drug-like properties and in vivo efficacy in a humanized mouse model of Plasmodium falciparum infection. The compound shows single digit nanomolar in vitro activity against P. falciparum and P. vivax clinical isolates, and potently blocks P. falciparum transmission to Anopheles mosquitoes. Genetic and biochemical studies identify AcAS as the target of the MMV693183-derived antimetabolite, CoA-MMV693183. Pharmacokinetic-pharmacodynamic modelling predict that a single 30 mg oral dose is sufficient to cure a malaria infection in humans. Toxicology studies in rats indicate a > 30-fold safety margin in relation to the predicted human efficacious exposure. In conclusion, MMV693183 represents a promising candidate for further (pre)clinical development with a novel mode of action for treatment of malaria and blocking transmission

    Developing an ecologically relevant heterogeneous biofilm model for dental-unit waterlines

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    This study monitored the biodiversity of microbes cultured from a heterogeneous biofilm which had formed on the lumen of a section of dental waterline tubing over a period of 910 days. By day two bacterial counts on the outlet-water showed that contamination of the system had occurred. After 14 days, a biofilm comparable to that of clinical waterlines, consisting of bacteria, fungi and amoebae had formed. This showed that the proprietary silver coating applied to the lumenal surface of the commercial waterline tubing failed to prevent biofilm formation. Molecular barcoding of isolated culturable microorganisms showed some degree of the diversity of taxa in the biofilm, including the opportunistic pathogen Legionella pneumophila. Whilst the system used for isolation and identification of contaminating microorganisms may underestimate the diversity of organisms in the biofilm, their similarity to those found in the clinical environment makes this a promising test-bed for future biocide testing
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